datetime: new format "p", same as "P" but returning "Z" for UTC

[gharlan]

ISO 8601 differentiates between local time (without time zone), UTC with letter "Z" and time offsets from UTC like "+02:00".
https://en.wikipedia.org/wiki/ISO_8601#Time_zone_designators

When formatting datetimes, it is sometimes desired to get the "Z" for UTC times and otherwise the offset.
But at the moment there are only the formatting chars "O" (for "+0200" etc.) and "P" (for "+02:00" etc.).

I suggest to add another formatting char "Q" lower case "p" which behaves the same as "P" but returns "Z" for UTC datetimes.

$datetime = new DateTime('2020-07-26 20:00:00', new DateTimeZone('UTC'));
$datetime->format('Y-m-d\TH:i:sP'); // '2020-07-26T20:00:00+00:00'
$datetime->format('Y-m-d\TH:i:sp'); // '2020-07-26T20:00:00Z'

$datetime = new DateTime('2020-07-26 20:00:00', new DateTimeZone('Europe/London'));
$datetime->format('Y-m-d\TH:i:sP'); // '2020-07-26T20:00:00+00:00'
$datetime->format('Y-m-d\TH:i:sp'); // '2020-07-26T20:00:00+00:00'

$datetime = new DateTime('2020-07-26 20:00:00', new DateTimeZone('Europe/Berlin'));
$datetime->format('Y-m-d\TH:i:sP'); // '2020-07-26T20:00:00+02:00'
$datetime->format('Y-m-d\TH:i:sp'); // '2020-07-26T20:00:00+02:00'

I'm not sure if it is useful enough to deserve a new formatting char. So don't worry about rejecting this proposal!

[derickr]

LGTM!

Can you make a ticket at bugs.php.net, so that we can add a line to the NEWS file too? Feel free to include that in this PR. The formatting of the NEWS file is finicky :-)

[gharlan]

Can you make a ticket at bugs.php.net, so that we can add a line to the NEWS file too? Feel free to include that in this PR. The formatting of the NEWS file is finicky :-)

Done. I hope everything is correct.

[cmb69]

[…], so that we can add a line to the NEWS file too? Feel free to include that in this PR.

I'd suggest not to add NEWS entries to PRs, because that can result in merge conflicts pretty quickly.

Anyhow, the merger should also add a note to UPGRADING, so that this feature addition will not be forgotten for the migration guide in the PHP manual. Thanks.

[cmb69]

Applied as a6e3ce4.